Environmental Influence on the Bond Between a Polymer Concrete Overlay and an Aluminum Substrate

About the report:

Chloride-ion-induced corrosion of reinforcing steel in concrete bridge decks has become a major problem in the United States. Latex-modified concrete, low-slump dense concrete, and hot-mix asphalt membrane overlays are some of the most used rehabilitation methods. Epoxy-coated reinforcing steel was developed and promoted as a long-term corrosion protection method by the Federal Highway Administration. However, recent evidence has suggested that epoxy-coated reinforcing steel will not provide adequate long-term corrosion protection. The Reynolds Metals Company developed an aluminum bridge deck system as a proposed alternative to conventional reinforced steel bridge deck systems. The deck consists of a polymer concrete overlay and an aluminum substrate. The purpose of this investigation was to evaluate the bond durability between the overlay and the aluminum substrate after specimens were conditioned in various temperature and humidity conditions. The different environmental conditionings all had a significant effect on the bond durability. Specimens conditioned at 30°C, 45 °C, and 60°C at 98 percent relative humidity all showed a decrease in interfacial bond strength after conditioning. There was also a decrease in the interfacial bond strength for the specimens conditioned in freezing and thawing cycles and specimens conditioned in a salt water soak. The only exposure condition that increased the bond strength was drying the specimens continuously in an oven at 60°C.

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